METAL-COMPLEXES OF THE CARBONIC-ANHYDRASE INHIBITOR METHAZOLAMIDE (HMACM) - CRYSTAL-STRUCTURE OF THE ZN(MACM)(2)(NH3)(2) - ANTICONVULSANT PROPERTIES OF THE CU(MACM)(2)(NH3)(2)(H2O)

Complexes of Co(II), Cu(II), and Zn(II) with deprotonated methazolamid e and ammonia are synthesized and characterized. The complex Zn(macm)( 2)(NH3)(2) crystallizes in the monoclinic C2/c space group with a = 13 .468(1), b = 6.759(1), c = 23.014(2) Angstrom, beta = 90.27(1), and Z = 4. The structure was refined to R = 0.049 (R(w) = 0.053). The Zn(II) ion is coordinated to two deprotonated sulfonamido nitrogen atoms of the macm(-) ligand and two nitrogen atoms of the ammonia ligands in a distorted tetrahedron. The Zn(macm)(2)(NH3)(2) complex is shown to be a simple model for the methazolamide inhibition of CA. EHMO calculatio ns applied to fractional coordinates of the Zn(macm)(2)(NH3)(2) comple x indicate that the atomic orbitals of the Zn do not contribute to HOM O and LUMO of the complex. The characteristics of the Cu(macm)(2)(NH3) (3)(H2O) as an anticonvulsant agent are tested.